Pilot burner



July. 16, 1957 c'. E. HAJNY 2,799,331

PILOT BURNER Original Filed July 18. 1948 PILOT BURNER Charles E. Hajny,Milwaukee, Wis., assignor to Baso Inc, Milwaukee, Wis., a corporation ofWisconsin Continuation of application Serial No. 39,339, July 18, 1948.This application July 23, 1954, Serial No. 445,268

Claims. (Cl. 158-123) This invention is a continuation of my applicationSerial No. 39,339, now abandoned, filed July 18, 1948, and relates, ingeneral, to gas burners, and has particular relation to an improvedpilot burner for use with various types of gas appliances.

One of the main objects of the invention is to provide an improved formof pilot burner having an improved form of air inlet; more particularly,a primary air inlet which extends peripherally about the spud of theburner and is formed by supporting the spud in position within theadjacent end of the pilot burner body and with a clear or unobstructedchannel type peripheral air inlet space therebetween.

Another object of the invention is to provide an improved form of pilotburner for use with a thermoelectric generator and an improved form ofbracket or mounting means for the pilot burner and thermoelectricgenerator with which constant flame characteristics of predeterminedcharacter and in appropriate position to assure ignition of the mainburner and proper heating of the hot junction means of thethermoelectric generator are at all times eflectively maintained.

Another object of the invention is to provide an improved form ofmounting for the pilot burner, and an improved form of mounting for thethermoelectric generator which adapts itself to the pilot burnermounting, and which mountings maintain the thermoelectric generatoreffectively at all times in the desired relation with respect to thethermoelectric generator heating flame of the pilot burner and the mainburner igniting flame of the pilot burner in the desired relation withrespect to the main burner.

Another object of the invention is to provide an improved pilot burnerof the character described wherein a turbulent flow is maintained at alltimes, although each individual gas stream might be in a streamlinecondition; also a pilot burner wherein, in operation, the intersectionof the two or more streams of fluid fuel causes the fluid fuel to fanout to provide a large, turbulent mass within which the air admittedthrough the annular air inlet opening is intimately intermixed, andwherein a turbulent condition is established in proximity to theposition where the air is entrained and the resulting fuel mixture thenpasses to flame position remote from the intersection of the fuelstreams.

Another object of the invention is to provide an improved pilot burnerof the character described wherein constant flame characteristics ofpredetermined character are maintained over the complete range ofoperating pressures and any operating temperature which assures lightingof the main burner and proper heating of the hot junction of thethermoelectric generator under all operating conditions and againstfalse or erroneous shut-01f of the fuel by the thermoelectric safetymeans, such as occurred heretofore in the art where proper heating ofthe thermoelectric generator was not maintained notwithstanding the factthat the system was not in condition requiring shut off of the fuelsupply by the thermoelectric safety control means.

Another object of the invention is to provide an improved form of pilotburner of the character described having the novelty and advantages setforth and characterized by its simplicity in construction, its economyin manufacture, its adaptability for use with diiferent appliances, andits efiectiveness for accomplishing the results set forth.

Further objects and advantages of the invention will appear from thefollowing detailed description, taken in connection with theaccompanying drawing in which:

Figure 1 is a front elevational view of one form of pilot burnerembodying the present invention;

Figure 2 is a top plan view of the pilot burner shown in Figure 1;

Figure 3 is an end view of the pilot burner shown in Figure 1;

Figure 4 is a fragmentary axial sectional view, partially in elevation,taken on the line 4--4 of Figure 1;

Figure 5 is a front elevational view of another form of pilot burnerembodying the present invention;

Figure 6 is an end view of the pilot burner shown in Figure 5 and Figure7 is a fragmentary back view of the pilot burner shown in Figure 5.

Referring now to the drawings, the device shown in Figures 1 to 4,inclusive, comprises a bracket or mounting 1 of generally channel orU-shaped section and having a back wall 2, an outstanding upper arm 3and an outstanding lower arm 4 in parallel spaced relation with respectto the arm 3. The arms 3 and 4 constitute spaced pilot burner mountingparts, it being understood that the bracket may have only one armprovided with such parts or a plurality of arms as shown in theillustrated embodiment of the invention. The bracket 1 may be made ofcold rolled steel, or other suitable material, and may be cold rolled orof other suitable form.

The ends of the back wall 2 are shown with apertured mounting lugs 5 formounting the bracket in the desired position on a suitable support. Thelugs 5 have apertures as shown in the drawing, through which screws orother suitable attachment means may be passed and screwed into orotherwise engaged with various forms of supports (not shown) to attachthe bracket in any desired one of various positions.

A strip 6 has scarfed ends 7 secured by pressed fit or by brazing,soldering or otherwise in notches in the outer edges of the arms 3 and4. The shoulders formed by scarfing the ends of the strip 6 engage innersurfaces of the arms 3 and 4, and constitute spacing means between theouter ends of these arms. The strip 6 may have apertures at 8, and theback wall 2 may have similar apertures 9 in register with the apertures8. The apertures 8 and 9 may, if desired, be used for attaching thebrackets in various positions to suitable supports by screws or otherattachment means.

The pilot burner body 10 is of generally tubular form, having at itslower end a passage 11 of enlarged diameter with a reduced diameterpassage 12 extending upwardly from the passage 11. The fundamentalmixing and injecting power of the plurality of angular fluid fuelstreams according to the present invention as will hereinafter appear,eliminates the need of a venturi in the burner throat and provides forair intake of increased proportions. Therefore the passage 11 is showndevoid of venturi form, although this passage may be of venturi formwithin the scope of the present invention.

illustration has an annular groove 14 through which a' port 15 opensradially outwardly from the outer end of the passage 12 for maintainingan ignition flame 16 for a main burner. A second port .17 opensoutwardly from the passage 12 through the grooved part 14 of theburner'tip for maintaining a pilot flame 18 for heating the hot junction19 of the thermoelectric generator 20. In the illustrated embodiment ofthe invention, the port 17 is spaced approximately'90 from the port 15,although this may, of course, vary according to the position of the mainburner relative to the hot junction of the thermoelectric generator. Theports 15 and 17 are connected by a slit 21 which extendscircumferentially within the groove 14 whereby the ignition andthermoelectric generator heating flames l6 and 18 are joined together,making it impossible for either flame to burn without the other.

The lower end of the pilot burner body 10 is of externally reduceddiameter, and extends through an opening 22 in bracket arm 3 and mayhave fixed pressed fit therein. An external flange or shoulder 23 ofannular form on the pilot burner body 10 abuts the adjacent surface ofthe arm.

The lower bracket arm 4 has an internally threaded opening 24- coaxialwith the opening 22. Fluid fuel, such, for example, as gas, for thepilot burner is supplied through a tube or pipe 25 joined by a suitablecoupling member 26 to the burner inlet fitting 27. The coupling member26 is screwed into the adjacent end of the inlet fitting 27, and theinlet fitting is screwed into the opening 24 with the spud or inner endthereof supported in position within the adjacent end of the burner body10 and a peripheral or annular primary air inlet space 28 extendingannularly between the exterior of the spud and the interior of theadjacent end of the pilot burned body.

The inlet fitting or spud 27 has an external nut-like portion ofhexagonal or polygonal form for receiving a wrench or other suitabletool for applying and removing the spud. The coupling member 26 also hasan external nut-like portion of polygonal form for receiving a wrench orother suitable tool for connecting the fuel supply tube to the inletfitting and detaching the same therefrom. The fitting 27 has an internalpassage 29 for receiving gas from the tube or pipe 25. The inner or jetend of the spud 27 has a transverse wall 3t) provided with a plurality(two being shown) of orifices 31 which are directed at an angle to theaxis of the fitting so that the two gas streams will intersect eachother at 32-.

With the gas streams intersecting at 32, a turbulent flow is maintainedat all times, although each individual gas stream might be in astreamline flow condition. In operation, the intersection of the two ormore streams of fluid fuel causes the fluid fuel to fan out to provide alarge, turbulent mass within which the air admitted through the annularair inlet opening is intimately intermixed. A turbulent condition isestablished in proximity to the position where the air is entrained, andthe resulting fuel mixture then passes to flame position remote from theintersection of the fuel streams.

As a result, constant flame characteristics of predetermined characterare maintained over the complete range of operating pressures and anyoperating temperature. This assures lighting of the main burner andproper heating of the hot junction of the thermoelectric generator underall operating conditions and against false or erroneous shut-off of thefuel by the thermoelectric safety control means, such as occurredheretofore in the art where proper heating of the thermoelectricgenerator is not maintained notwithstanding the fact that the system isnot in condition requiring shut-off of the fuel supply by thethermoelectric safety control means.

It is also believed that the angular streams of fuel striking togetherwhere they intersect at 32 removes energy and eliminates or reducesvariations in pressure in the fuel mixture passing to flame position.

In thcillustrated embodiment of the, invention, the ends of the orifices31 are shown countersunk at 33 into the end of the fitting 27 to avoiddistortion of the ends of the orifices 31 by contact with the end of thefitting. 'While the thermoelectric generator 20 may be of any othersuitable form (thermocouple or thermopile), the one shown in the drawingis of the type shown and described in Oscar I. Leins Patent No.2,126,564, August 9, 1938.

' couple member 34- and an inner metallic thermocouple member 35disposed within the tubular thermocouple member and joined to the endthereof to form the hot junction 19.

A metallic tubular member or sleeve 36 is connected to the end of thetubular thermocouple member 34 to form a. cold junction at 37, and atubular lead conductor 33 is connected tov the opposite end of thesleeve 36. An internally disposed lead conductor extends through tubularlead conductor 38 and sleeve 36, and is connected to the innerthermocouple member 35 to form an inner enclosed cold junction 41. Theopposite end of the conductor 40 has a terminal tip 42 insulated at 43from an annular terminal 44 on the adjacent end of tubular conductor 38.A coupling sleeve or connector'nut 45 freely surrounds the tubularconductor 38 and is threaded at 46 to be screwed into a cooperating partof a thermoelectric control device (not shown) to connect the conductors38 and 40 in circuit with the electromagnet thereof, as well known inthe art.

The bracket arm 3 has an opening 47 spaced laterally from the pilotburner. mounting, and the bracket arm 4'has an internally threadedopening 48 in alignment or axial registration with the open'mg 47; Theopening 48 is of larger diameter than the opening 47, and the sleeve 36of the thermoelectric generator 20 has a pair of longitudinally spacedintegral annular ribs or shoulders 49 and St) on the external surfacethereof. The shoulders 49 and 50 are of outside diameter that will passfreely through the opening 48 for insertion of the thermocouple intoplace in the bracket arms 3 and 4, as shown.

The outside diameter of at least the shoulder 49 is larger than thediameter of the opening 47 so as to abut the inner side of arm 3 insecuring the thermocouple in place. A coupling member or compression nutand sleeve 51 loosely surrounds the conductor 33 and is adapted looselyto surround the adjacent end of the sleeve 36. The nut 51 has apolygonal portion 52 for engagement by a wrench or other suitable tool,and is threaded at 53 to be screwed into the opening 48. By screwing thenut 51 into the opening 48, its inner end abuts the shoulder 50 andforces the shoulder 49 against the inner side of arm 3, thus securingthe thermocouple in place in the bracket. The thermocouple mountingadapts itself to the pilot burner mounting and positions the hotjunction of the thermocouple where it will at all times be properlyheated by the flame 18.

The advantages of the properly dimensioned, unobstructed peripheral airchannel are:

(1) The chances of clogging a circumferential channel by dust and lintis much less than would be the case with air holes or slots.

(2) It is almost impossible to ignite the pilot gas as it issues fromthe spud, even when a flame is played around the air intake.

3) Where two or more orifices are used, the clear channel peripheral airinlet permits the location of these orifices in any position circularlyor azimuthally around the main axis of the air channel or of the orificespud axis with any such rotation in position having no effect on theamount of primary air inspiration, because of said circular andunobstructed structure. Azimuthal variations in multiple orificeposition occur for such reasons as varying degree of tightness of theorifice spud It comprises an outer metallic tubular thermoin the mainpilot body or in mechanical variations during production.

The embodiment of the invention shown in Figures 5, 6, and 7, is, ingeneral, similar to the embodiment shown in Figures 1 to 4 inclusive. Inthis case, the U-shaped bracket 1', instead of having a back wall, hasan end wall 55 provided with apertures 56. The upper end of the pilotburner body has a tip part 57 secured thereto and extending obliquelytherefrom. The outer end of the tip part 57 is of reduced diameter at 58and has a tip shield 5? secured on its outer end as by pressed fitforming an annular groove between the shield 59 and the outer end of theinner enlarged portion of the tip part.

Ports 60 and 61 open radially outwardly within the groove thus formed;the port 60 maintaining an ignition flame 62 for a main burner, and theport 61 maintaining a pilot flame 63 for heating the hot junction of thethermoelectric generator. As before, the ports 60 and 61 are connectedby a slit 21' which extends circumferentially within the groove wherebythe ignition and thermoelectric generator heating flames 62 and 63 arejoined together, making it impossible for either flame to burn withoutthe other. Instead of a slit, the ports may be connected by interveningsmaller holes to act as carrier ports.

A bracket member 64 is fixed by pressed fit, brazing, soldering orotherwise edgewise between the arms 3 and 4' at one side of the bracket1, and has integral lugs 65 secured in notches in the adjacent edges ofthe arms 3' and 4'. The bracket member 64 has an obliquely turned lug 66provided with apertures 67 for mounting the bracket in the desiredposition upon a suitable support. The remaining parts of the deviceshown in Figures 5, 6, and 7 are similar to the parts of the precedingembodiment of the invention, and are designated by primed referencecharacters corresponding with the ref erence characters used in Figures1 to 4, inclusive.

The embodiments of the invention shown in the drawings are forillustrative purposes only, and it is to be expressly understood thatsuch drawings and the accompanying specification are not to be construedas a definition of the limits or scope of the invention, reference beinghad to the appended claims for that purpose.

I claim:

1. In a device of the class described, in combination, a supportingbracket of generally U-shaped section having integral parallel first andsecond arms, a pilot burner body having a tubular inlet end supported ina first opening in said first arm, a fuel inlet fitting supported in afirst opening in said second arm and projecting into the tubular inletend of said pilot burner body in annularly spaced relation thereto, saidfirst arm having a second opening, said second arm having a secondopening of larger diameter than the second opening in said first arm, athermoelectric generator having first and second spaced annularshoulders of sizes which will pass through the second opening in saidsecond arm but with the first shoulder of a size incapable of passingthrough the second opening in said first arm so that it will seatagainst said first arm adjacent to said second opening, and acompression nut screwed through the second opening in said second armfor endwise abutment with the second shoulder on said thermoelectricgenerator to secure the thermoelectric generator in place in relation tothe pilot burner body.

2. In a device of the class described, in combination, a supportingbracket of generally U-shaped section having a first arm provided with apair of spaced openings and having a second arm parallel with and spacedfrom said first arm, a pilot burner head having a tubular part insertedthrough one of the openings in the first arm from the outer side of saidarm and having at least one flame port, an abutment rigidly joined tosaid pilot burner head and engageable with the outer side of said firstarm by insertion of the tubular part through one of said openings tolimit the movement of the tubular part through said opening and toposition the flame port in predetermined relation to said arm, athermoelectric generator inserted through the other opening of saidfirst arm from the inner side of said am, said thermoelectric generatorhaving at least one hot junction, a'n abutment rigidly joined to saidthermoelectric generator and engageable with the inner side of saidfirst arm by insertion of the thermoelectric generator through the otheropening of said arm to limit the movement of the thermoelectricgenerator through said other opening and to position the hot junction inpredetermined relation to said flame port, said openings being spaced anamount to provide a predetermined spacing of said thermoelectricgenerator from said burner head, and a fuel inlet fitting supported inan opening in said second arm and projecting coaxially into the tubularpart of the pilot burner head with an annular air inlet passagetherebet'ween, said fuel inlet fitting having a plurality of fuelorifices arranged with their axes angula-rly disposed relative to eachother for directing fuel into the pilot burner head in a plurality ofconverging streams which intersect at a focus within the pilot burnerhead and beyond the adjacent end of the fuel inlet fitting.

3. In a device of the class described, in combination, a supportingbracket of generally U-shaped session having a first arm provided with apair of spaced openings and having a second arm parallel with and spacedfrom said first arm, a pilot burner head having a tubular part insertedthrough one of the openings in the first arm from the outer side of saidarm and having at least one flame port, an abutment rigidly joined tosaid pilot burner head and engageable with the outer side of said firstbracket arm by insertion of the tubular part through one of saidopenings to limit the movement of the tubular part through said openingand to position the flame port in predetermined relation to said arm, athermoelectric gen erator inserted through the other opening of saidfirst arm from the inner side of said arm, said thermoelectric generatorhaving at least one hot junction, an abutment rigidly joined to saidthermoelectric generator and engageable with the inner side of saidfirst arm by insertion of the thermoelectric generator through the otheropening of said arm to limit the movement of the thermoelectricgenerator through said other opening and to position the hot junction inpredetermined relation to said flame port, said openings being spaced anamount to provide a predetermined spacing of said thermoelectricgenerator from said burner head, and a fuel inlet fitting supported onsaid second arm and projecting coaxially into the tubular part of thepilot burner head with an annular air inlet passage therebetween.

4. In a device of the class described, in combination, a supportingbracket of generally U-shaped section having a first arm provided with apair of spaced openings and having a second arm parallel with and spacedfrom said first arm, said second arm having a pair of openings one inaxial alignment with each of the openings in the first arm, a pilotburner head having a tubular part inserted through one of the openingsin the first arm from the outer side of said arm and having at least oneflame port, an abutment rigidly joined to said pilot burner head and anengageable with the outer side of said first arm by insertion of thetubular part through one of said openings to limit the movement of thetubular part through said opening and to position the flame port inpredetermined relation to said arm, a thermoelectric generator insertedthrough the other opening of said first arm from the inner side of saidarm, said thermoelectric generator having at least one hot junction, anabutment rigidly joined to said thermoelectric generator and engageablewith the inner side of said first bracket arm by insertion of thethermoelectric generator through the other opening of said arm to limitthe movement of the thermoelectric generator through said other openingand to position the hot junction in predetermined relation to said flameport, said openings being spaced an amount to provide a predeterminedspacing of said thermoelectric generator from said burner head, a fuelinlet fitting supported in one of the openings in said second arm andprojecting coaxially into the tubular part of the pilot burner head withan annular air inlet passage therebetween, and a nut screwed into theother opening in said second arm into engagement with a second abutmenton the thermoelectric generator to clamp the first-mentioned abutment onthe thermoelectric generator in engagement with the inner side of thefirst mentioned arm of the bracket.

5. In a device of the class described, in combination, a supportingbracket having first and second spaced arms each formed with an opening,a pilot burner body carried by said first arm and having a tubuler inletend, a fuel inlet fitting supported in the opening in said second armand projecting into the tubular inlet end of said pilot burner body inannularly spaced relation thereto, a ther- References Cited in the fileof this patent UNITED STATES PATENTS 1,175,888 ODowd Mar. 14, 19161,399,788 Needham Dec. 13, 1921 1,794,869 Schifferle Mar. 3, 19311,875,394 Richford Sept. 6, 1932 2,321,689 Lightfoot et a1. June 15,1943 2,355,216 Guelson Aug. 8, 1944 2,412,348 Mercier Dec. 10, 19462,430,887 Ray Nov. 18, 1947

